Thinly slice as many turnips as you need, one for each sushi roll. Soak in salt water, drain, and squeeze out the water after they have wilted.
Cut the shiso in half lengthwise, then cut diagonally for each piece. Prepare the nori seaweed to wrap.
Shape the sushi rice into a barrel, smear on a dab of wasabi paste, and place a shiso leaf on top. Dip a slice of turnip in sushi vinegar, lay it on the rice and adjust the shape. Wrap with a strip of nori.